CN110939713A

CN110939713A - A modified gear and harmonic reducer

Info

Publication number: CN110939713A
Application number: CN201911365997.XA
Authority: CN
Inventors: 陈勰; 陈伟南
Original assignee: Shenzhen Zhuo Zhuo Harmonic Drive Technology Co Ltd
Current assignee: Shenzhen Zhuo Zhuo Harmonic Drive Technology Co Ltd
Priority date: 2019-12-26
Filing date: 2019-12-26
Publication date: 2020-03-31

Abstract

The invention relates to a trimming gear, comprising a cylindrical body with an open end and a closed end; the outer side of the open end is provided with a plurality of external teeth along the circumference, along the direction from the open end to the closed end, Each of the external teeth has a first tooth segment and a second tooth segment, and the distance between the top of the second tooth segment and the central axis of the cylinder gradually decreases. The present invention also relates to a harmonic reducer, comprising the above-mentioned trimming gear, wherein the trimming gear is arranged in an inner cavity, and the outer teeth mesh with the inner teeth; and a rigid wheel is provided with an inner cavity, and the cavity wall of the inner cavity is The inner teeth are arranged on the upper part; the wave generator is also included, and the wave generator is connected in the cylinder. The invention can increase the contact length of the tooth surface with the inner teeth of the rigid wheel, thereby dispersing the acting force on the tooth surface, and realizing the purpose of reducing the wear of the tooth surface, improving the running stability and reducing the noise during operation.

Description

Shape-modifying gear and harmonic reducer

Technical Field

The invention relates to the field of harmonic reducers, in particular to a shape modification gear and a harmonic reducer.

Background

In the harmonic gear reducer, the tooth shapes of a flexible gear and a rigid gear directly influence the performance such as the precision service life of the harmonic reducer. In the related art, the tooth profiles of the flexible gear and the rigid gear are straight tooth involute type or double circular arc type, and both the tooth profile of the flexible gear and the tooth profile of the rigid gear are uniform-section tooth profiles, as shown in fig. 1 and 2. After the wave generator is installed in the interior of one end (for example, the right end in fig. 1) of the flexible gear, the right end is expanded and deformed due to the abutting of the wave generator, and the farther away from the right end, the smaller the deformation of the flexible gear is, namely, the flexible gear is integrally of a conical structure with the small left end and the large right end, so that the farther away from the right end is caused, the smaller the meshing area of the flexible gear and the teeth on the steel gear is, part of the teeth can bear larger acting force due to the meshing mode, the teeth are easily abraded, in addition, the insufficient meshing area can also influence the running stability, and the noise in running is increased.

Disclosure of Invention

The present invention solves at least one of the technical problems of the related art to some extent. To this end, it is an object of an embodiment of the present invention to provide a modified gear capable of increasing the tooth surface contact area of a rigid gear and a flexible gear.

The technical scheme adopted by the embodiment of the invention is as follows:

in a first aspect, a modified gear is provided, comprising a barrel having an open end and a closed end; the outside of open end is equipped with a plurality of outside teeth along the circumference, along the direction of open end to closed end, every outside tooth has first tooth section and second tooth section, and the distance of the axis of the top of second tooth section apart from the barrel reduces gradually.

The invention has the beneficial effects that:

the shape-modifying gear can increase the contact length of the tooth surface of the internal tooth of the rigid gear, so that the acting force borne by the tooth surface can be dispersed, and the purposes of reducing the tooth surface abrasion, improving the running stability and reducing the running noise are achieved.

In some embodiments of the invention, the distance of the tip of the first tooth segment from the central axis is kept constant.

In some embodiments of the invention, the barrel is a cylindrical barrel, and the distance from the top of the second tooth segment to the inner side wall of the barrel gradually decreases in the direction from the open end to the closed end.

In some embodiments of the invention, the tooth height of the first tooth segment remains constant.

In some embodiments of the invention, the profile line of the tip of the second tooth segment includes an angle α with respect to the central axis that is 0.01 to 0.05 times the magnitude of the pressure angle of the tooth form.

In some embodiments of the invention, the length of the second tooth segment is 0.2 to 0.4 times the length of the outer tooth.

In a second aspect, the invention further provides a harmonic reducer, which comprises the modified gear, wherein the modified gear is arranged in the inner cavity, and external teeth are meshed with the internal teeth; the rigid wheel is provided with an inner cavity, and the cavity wall of the inner cavity is provided with inner teeth; the wave generator is connected in the cylinder.

Drawings

Fig. 1 is a sectional view of a flexspline in the related art.

Fig. 2 is an enlarged view of the region I in fig. 1.

Fig. 3 is a cross-sectional view of one embodiment of the present invention.

Fig. 4 is an enlarged view of region II in fig. 3.

FIG. 5 is a schematic view of an embodiment of the present invention in use engaged.

Fig. 6 is an enlarged view of the region III in fig. 5.

Detailed Description

This section will describe in detail embodiments of the present invention, which are illustrated in the accompanying drawings, the purpose of which is to supplement the description of the text of the description with figures so that each technical feature and the whole technical solution of the embodiments of the present invention can be intuitively and visually understood, but it should not be construed as limiting the scope of the present invention.

In the description of the present invention, if an orientation description is referred to, for example, the orientations or positional relationships indicated by "upper", "lower", "front", "rear", "left", "right", etc. are based on the orientations or positional relationships shown in the drawings, only for convenience of describing the present invention and simplifying the description, but not for indicating or implying that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. If a feature is referred to as being "disposed," "secured," or "connected" to another feature, it can be directly disposed, secured, or connected to the other feature or be indirectly disposed, secured, or connected to the other feature.

In the description of the embodiments of the present invention, if "a number" is referred to, it means one or more, if "a plurality" is referred to, it means two or more, if "greater than", "less than" or "more than" is referred to, it is understood that the number is not included, and if "greater than", "lower" or "inner" is referred to, it is understood that the number is included. If reference is made to "first" or "second", this should be understood to distinguish between features and not to indicate or imply relative importance or to implicitly indicate the number of indicated features or to implicitly indicate the precedence of the indicated features.

In addition, unless defined otherwise, technical and scientific terms used in the embodiments of the present invention have the same meaning as commonly understood by one of ordinary skill in the art. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Referring to fig. 3, a schematic cross-sectional view of one embodiment of the present invention is shown. In this embodiment, the barrel 1 of the modified gear is cup-shaped, and in other embodiments, the barrel 1 of the modified gear is top-hat-shaped. Wherein one end (e.g., the right end in fig. 3) of the barrel 1 is an open end 10 and the other end (e.g., the left end in fig. 3) is a closed end 20, the term "closed end 20" herein refers to being closed relative to the fully open end 10 and does not mean that the closed end 20 is fully closed, e.g., the closed end 20 in fig. 3 may have a through hole.

Referring to fig. 4, the outer side of the open end 10 of the barrel 1 is circumferentially provided with a plurality of external teeth 2, and each external tooth 2 has a first tooth section 21 and a second tooth section 22 in a direction from the closed end 20 to the open end 10 (for example, from left to right in fig. 3), and the distance from the top of the first tooth section 21 to the central axis of the barrel 1 is kept constant, and the distance from the top of the second tooth section 22 to the central axis of the barrel 1 is gradually reduced and is in a downward slope shape towards the open end. Specifically, in this embodiment, the manner in which the distance of the top of the second tooth section 22 from the central axis of the cylinder 1 gradually decreases is implemented as follows: so that the distance from the top of the second tooth segment 22 to the inner side wall of the cylinder 1 is gradually reduced.

In some embodiments of the present invention, the wall thickness of the cylinder 1 in the range of the second tooth section 22 is also gradually reduced in this embodiment, that is, the outer contour of the cylinder 1 in the range of the second tooth section 22 is conical to ensure that the tooth height of the second tooth section 22 is constant, and to avoid weakening the strength of the second tooth section 22.

In some embodiments of the present invention, the profile line of the top of the second tooth section 22 includes an angle α with respect to the central axis that is 0.01 to 0.05 times the pressure angle of the tooth form.

In some embodiments of the invention, the length of the second tooth section 22 is 0.2 to 0.4 times the length of the outer tooth 2.

In some embodiments of the invention, a harmonic reducer using the modified gear as a flexible gear is also disclosed, and the harmonic reducer further comprises a wave generator 3 and a rigid gear 4; in the embodiment, the modification gear is arranged in an inner cavity of the rigid wheel 4, inner teeth are arranged on the inner cavity, external teeth 2 on the modification gear can be meshed with the inner teeth of the rigid wheel 4, and a wave generator 3 is arranged in the inner cavity of the modification gear.

In the embodiment, the modified gear is used as a flexible gear of the harmonic reducer, and the inclined second gear section 22 can inhibit the flexible gear from deforming after the wave generator is installed in the flexible gear, so that the contact length of the external teeth 2 of the flexible gear and the tooth surfaces of the internal teeth of the rigid gear can be increased, the stress of the installation position of the wave generator of the flexible gear can be reduced, the starting torque of the harmonic reducer is reduced, and the transmission efficiency is improved; in addition, referring to fig. 5 and 6, since the area of the meshing area is increased, the present embodiment can also disperse the acting force borne by the tooth surface, thereby reducing the abrasion of the tooth surface, improving the running stability, and reducing the running noise.

The embodiments of the present invention have been described in detail, but the present invention is not limited to the embodiments, and those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and such equivalent modifications or substitutions are included in the scope of the present invention defined by the claims. Furthermore, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.

Claims

1. A trimming gear, characterized in that it comprises a cylindrical body having an open end and a closed end; the outer side of the open end is provided with a plurality of external teeth along the circumference, along the open end to the closed end; In the direction of the end, each of the external teeth has a first tooth segment and a second tooth segment, and the distance between the top of the second tooth segment and the central axis of the cylinder gradually decreases.

2 . The dressing gear of claim 1 , wherein the distance between the top of the first tooth segment and the central axis is kept constant. 3 .

3 . The trimming gear according to claim 1 , wherein the barrel is a cylindrical barrel, and along the direction from the open end to the closed end, the top of the second tooth segment reaches the The distance between the inner side walls of the cylinder gradually decreases.

4. The trim gear of claim 3, wherein the tooth height of the second tooth segment remains constant.

5 . The trimming gear according to claim 1 , wherein the included angle α of the contour line of the top of the second tooth segment relative to the central axis is 0.01-0.05 times the pressure angle of the tooth shape. 6 . .

6. The trim gear of claim 1, wherein the length of the second tooth segment is 0.2 to 0.4 times the length of the outer teeth.

7. A harmonic reducer, characterized in that it comprises

The rigid wheel is provided with an inner cavity, and the cavity wall of the inner cavity is provided with internal teeth;

The trim gear according to any one of claims 1 to 6, wherein the trim gear is provided in the inner cavity, and the outer teeth mesh with the inner teeth;

a wave generator connected in the barrel.